Functional and morphological changes of the liver in patients with malabsorption syndrome

The dissertation examines functional and morphological changes of the liver in patients with malabsorption syndrome caused by gluten enteropathy and short bowel syndrome. The study aims to systematize the clinical manifestations of liver involvement in these conditions, to evaluate liver functional tests (primarily aminotransferase activity), and to analyze the morphological pattern of the liver, including steatosis and steatohepatitis, in relation to the etiology and severity of malabsorption syndrome. Particular attention is given to the features of the immune status of patients with and without markers of viral hepatitis, as well as to the effect of strict adherence to a gluten-free diet on liver functional parameters.

The practical significance of the work lies in substantiating the need for liver needle biopsy in patients with clinical and functional liver disturbances in the setting of malabsorption syndrome and in confirming lifelong adherence to a gluten-free diet as the key method of preventing liver involvement in gluten enteropathy.

The close anatomical and functional interconnection of various organs of the digestive system leads to the situation in which a disease affecting one section of the gastrointestinal tract inevitably involves a whole complex of other functionally related organs and systems in the pathological process [8]. Therefore, diseases of the small intestine frequently manifest with extraintestinal symptoms that complicate diagnosis.

Malabsorption syndrome (MS) is one of the principal manifestations of small intestinal diseases. The cause of MS development may vary. Thus, in gluten enteropathy (GEP) the main cause of malabsorption is hyperregenerative-type atrophy of the small intestinal mucosa, whereas in short bowel syndrome it is the reduction of the absorptive surface area and bacterial contamination of the remaining portion of the small intestine.

Insufficient intake of nutrients into the organism in this syndrome leads to metabolic disturbances, which account for the intestinal and extraintestinal manifestations of MS [13]. The most pronounced malabsorption develops in patients with GEP and in persons who have undergone massive resection of the small intestine.

Since the liver plays a central role in maintaining the chemical homeostasis of the organism, it is evident that the metabolic disturbances arising from nutrient deficiency may, first and foremost, affect its state [18]. There are isolated reports of a moderate increase in aminotransferase activity in a proportion of patients with celiac disease [36, 168], whereas in patients with resection of the small intestine such data are lacking. The clinical manifestations of liver involvement in MS have not been elucidated. Published data on the morphological pattern of the liver in GEP and SBS are highly contradictory. The relationship between the severity of MS, the character of functional disturbances, and the morphological pattern of the liver in patients with GEP and in patients with resection of the small intestine has not been studied.

Treatment of patients with MS is directed mainly at correcting the metabolic disorders that develop as a consequence of malabsorption, while the character of pathological changes in other organs, and in the liver in particular, is not always taken into account.

In this connection, an investigation of the state of the liver in patients with MS in relation to the etiological factor and the severity of malabsorption syndrome is of scientific and practical interest.

AIM OF THE STUDY

To assess the clinical, functional, and morphological changes of the liver in gluten enteropathy and short bowel syndrome in relation to the severity of malabsorption syndrome.

OBJECTIVES OF THE STUDY

1. To identify the characteristic features of clinical manifestations of liver involvement in patients with MS.

2. To study the functional state of the liver in gluten enteropathy and short bowel syndrome in relation to the severity of MS.

3. To evaluate the immune status of patients with gluten enteropathy and with short bowel syndrome.

4. To study the morphological pattern of the liver in gluten enteropathy and short bowel syndrome.

SCIENTIFIC NOVELTY

For the first time, a clinical assessment of the state of the liver in patients with GEP and SBS accompanied by varying severity of MS has been provided. It has been established that the dominant clinical manifestations in GEP and SBS are those of MS. Clinical manifestations characteristic of liver involvement are mild and occur only in a proportion of patients.

It has been revealed that changes in liver functional tests most often manifest as hyperaminotransferasemia. Other parameters of liver functional tests are disturbed considerably less frequently. It has been established that the frequency of elevated ALT and AST activity does not depend on the nosological form but is determined by the severity of MS accompanying the underlying disease.

For the first time, it has been established that disturbance of liver functional tests in the form of hyperaminotransferasemia occurs predominantly in patients with newly diagnosed GEP rather than in patients adhering to a gluten-free diet.

It has been shown that adherence to a gluten-free diet in the overwhelming majority of cases leads to normalization of liver functional tests, although in 13.8% of patients, despite strict adherence to a gluten-free diet, elevated aminotransferase levels persist for a long time.

It has been revealed that in patients with GEP and SBS without markers of viral hepatitis, changes in immune status in a proportion of patients are characterized by a moderate increase in IgG and IgA concentrations. In the presence of markers of viral hepatitis, the frequency of elevated levels of these immunoglobulins increases 2-3 times.

It has been established that the morphological pattern of the liver in MS most frequently is characterized by changes in the form of hepatic steatosis and the development of steatohepatitis.

PRACTICAL SIGNIFICANCE

Studies have shown that in patients with MS clinical signs characteristic of liver involvement are uncommon and therefore cannot be the main basis for establishing the diagnosis.

Among the functional disturbances of the liver in MS, the most informative are elevated aminotransferase activities.

Liver needle biopsy in patients with MS makes it possible to obtain the most complete information on the character of pathological changes in the liver. This investigation is indicated in all patients with MS who have clinical and functional liver disturbances.

One of the principal methods of preventing liver involvement in patients with GEP is strict lifelong adherence to a gluten-free diet.